From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/drivers/base/memory.c | 563 ++++++++++++++++++++++++--------------------------------
1 files changed, 243 insertions(+), 320 deletions(-)
diff --git a/kernel/drivers/base/memory.c b/kernel/drivers/base/memory.c
index e270abc..49eb142 100644
--- a/kernel/drivers/base/memory.c
+++ b/kernel/drivers/base/memory.c
@@ -19,29 +19,50 @@
#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/mm.h>
-#include <linux/mutex.h>
#include <linux/stat.h>
#include <linux/slab.h>
+#include <linux/xarray.h>
#include <linux/atomic.h>
#include <linux/uaccess.h>
-static DEFINE_MUTEX(mem_sysfs_mutex);
-
#define MEMORY_CLASS_NAME "memory"
+
+static const char *const online_type_to_str[] = {
+ [MMOP_OFFLINE] = "offline",
+ [MMOP_ONLINE] = "online",
+ [MMOP_ONLINE_KERNEL] = "online_kernel",
+ [MMOP_ONLINE_MOVABLE] = "online_movable",
+};
+
+int memhp_online_type_from_str(const char *str)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
+ if (sysfs_streq(str, online_type_to_str[i]))
+ return i;
+ }
+ return -EINVAL;
+}
#define to_memory_block(dev) container_of(dev, struct memory_block, dev)
static int sections_per_block;
-static inline int base_memory_block_id(int section_nr)
+static inline unsigned long memory_block_id(unsigned long section_nr)
{
return section_nr / sections_per_block;
}
-static inline int pfn_to_block_id(unsigned long pfn)
+static inline unsigned long pfn_to_block_id(unsigned long pfn)
{
- return base_memory_block_id(pfn_to_section_nr(pfn));
+ return memory_block_id(pfn_to_section_nr(pfn));
+}
+
+static inline unsigned long phys_to_block_id(unsigned long phys)
+{
+ return pfn_to_block_id(PFN_DOWN(phys));
}
static int memory_subsys_online(struct device *dev);
@@ -53,6 +74,13 @@
.online = memory_subsys_online,
.offline = memory_subsys_offline,
};
+
+/*
+ * Memory blocks are cached in a local radix tree to avoid
+ * a costly linear search for the corresponding device on
+ * the subsystem bus.
+ */
+static DEFINE_XARRAY(memory_blocks);
static BLOCKING_NOTIFIER_HEAD(memory_chain);
@@ -68,20 +96,6 @@
}
EXPORT_SYMBOL(unregister_memory_notifier);
-static ATOMIC_NOTIFIER_HEAD(memory_isolate_chain);
-
-int register_memory_isolate_notifier(struct notifier_block *nb)
-{
- return atomic_notifier_chain_register(&memory_isolate_chain, nb);
-}
-EXPORT_SYMBOL(register_memory_isolate_notifier);
-
-void unregister_memory_isolate_notifier(struct notifier_block *nb)
-{
- atomic_notifier_chain_unregister(&memory_isolate_chain, nb);
-}
-EXPORT_SYMBOL(unregister_memory_isolate_notifier);
-
static void memory_block_release(struct device *dev)
{
struct memory_block *mem = to_memory_block(dev);
@@ -93,69 +107,40 @@
{
return MIN_MEMORY_BLOCK_SIZE;
}
-
-static unsigned long get_memory_block_size(void)
-{
- unsigned long block_sz;
-
- block_sz = memory_block_size_bytes();
-
- /* Validate blk_sz is a power of 2 and not less than section size */
- if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) {
- WARN_ON(1);
- block_sz = MIN_MEMORY_BLOCK_SIZE;
- }
-
- return block_sz;
-}
+EXPORT_SYMBOL_GPL(memory_block_size_bytes);
/*
- * use this as the physical section index that this memsection
- * uses.
+ * Show the first physical section index (number) of this memory block.
*/
-
-static ssize_t show_mem_start_phys_index(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t phys_index_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
unsigned long phys_index;
phys_index = mem->start_section_nr / sections_per_block;
- return sprintf(buf, "%08lx\n", phys_index);
+
+ return sysfs_emit(buf, "%08lx\n", phys_index);
}
/*
- * Show whether the section of memory is likely to be hot-removable
+ * Legacy interface that we cannot remove. Always indicate "removable"
+ * with CONFIG_MEMORY_HOTREMOVE - bad heuristic.
*/
-static ssize_t show_mem_removable(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
- unsigned long i, pfn;
- int ret = 1;
- struct memory_block *mem = to_memory_block(dev);
-
- if (mem->state != MEM_ONLINE)
- goto out;
-
- for (i = 0; i < sections_per_block; i++) {
- if (!present_section_nr(mem->start_section_nr + i))
- continue;
- pfn = section_nr_to_pfn(mem->start_section_nr + i);
- ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
- }
-
-out:
- return sprintf(buf, "%d\n", ret);
+ return sysfs_emit(buf, "%d\n", (int)IS_ENABLED(CONFIG_MEMORY_HOTREMOVE));
}
/*
* online, offline, going offline, etc.
*/
-static ssize_t show_mem_state(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
{
struct memory_block *mem = to_memory_block(dev);
- ssize_t len = 0;
+ const char *output;
/*
* We can probably put these states in a nice little array
@@ -163,71 +148,25 @@
*/
switch (mem->state) {
case MEM_ONLINE:
- len = sprintf(buf, "online\n");
+ output = "online";
break;
case MEM_OFFLINE:
- len = sprintf(buf, "offline\n");
+ output = "offline";
break;
case MEM_GOING_OFFLINE:
- len = sprintf(buf, "going-offline\n");
+ output = "going-offline";
break;
default:
- len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
- mem->state);
WARN_ON(1);
- break;
+ return sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n", mem->state);
}
- return len;
+ return sysfs_emit(buf, "%s\n", output);
}
int memory_notify(unsigned long val, void *v)
{
return blocking_notifier_call_chain(&memory_chain, val, v);
-}
-
-int memory_isolate_notify(unsigned long val, void *v)
-{
- return atomic_notifier_call_chain(&memory_isolate_chain, val, v);
-}
-
-/*
- * The probe routines leave the pages uninitialized, just as the bootmem code
- * does. Make sure we do not access them, but instead use only information from
- * within sections.
- */
-static bool pages_correctly_probed(unsigned long start_pfn)
-{
- unsigned long section_nr = pfn_to_section_nr(start_pfn);
- unsigned long section_nr_end = section_nr + sections_per_block;
- unsigned long pfn = start_pfn;
-
- /*
- * memmap between sections is not contiguous except with
- * SPARSEMEM_VMEMMAP. We lookup the page once per section
- * and assume memmap is contiguous within each section
- */
- for (; section_nr < section_nr_end; section_nr++) {
- if (WARN_ON_ONCE(!pfn_valid(pfn)))
- return false;
-
- if (!present_section_nr(section_nr)) {
- pr_warn("section %ld pfn[%lx, %lx) not present",
- section_nr, pfn, pfn + PAGES_PER_SECTION);
- return false;
- } else if (!valid_section_nr(section_nr)) {
- pr_warn("section %ld pfn[%lx, %lx) no valid memmap",
- section_nr, pfn, pfn + PAGES_PER_SECTION);
- return false;
- } else if (online_section_nr(section_nr)) {
- pr_warn("section %ld pfn[%lx, %lx) is already online",
- section_nr, pfn, pfn + PAGES_PER_SECTION);
- return false;
- }
- pfn += PAGES_PER_SECTION;
- }
-
- return true;
}
/*
@@ -236,7 +175,7 @@
*/
static int
memory_block_action(unsigned long start_section_nr, unsigned long action,
- int online_type)
+ int online_type, int nid)
{
unsigned long start_pfn;
unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
@@ -246,10 +185,7 @@
switch (action) {
case MEM_ONLINE:
- if (!pages_correctly_probed(start_pfn))
- return -EBUSY;
-
- ret = online_pages(start_pfn, nr_pages, online_type);
+ ret = online_pages(start_pfn, nr_pages, online_type, nid);
break;
case MEM_OFFLINE:
ret = offline_pages(start_pfn, nr_pages);
@@ -275,7 +211,7 @@
mem->state = MEM_GOING_OFFLINE;
ret = memory_block_action(mem->start_section_nr, to_state,
- mem->online_type);
+ mem->online_type, mem->nid);
mem->state = ret ? from_state_req : to_state;
@@ -292,17 +228,14 @@
return 0;
/*
- * If we are called from store_mem_state(), online_type will be
- * set >= 0 Otherwise we were called from the device online
- * attribute and need to set the online_type.
+ * When called via device_online() without configuring the online_type,
+ * we want to default to MMOP_ONLINE.
*/
- if (mem->online_type < 0)
- mem->online_type = MMOP_ONLINE_KEEP;
+ if (mem->online_type == MMOP_OFFLINE)
+ mem->online_type = MMOP_ONLINE;
ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
-
- /* clear online_type */
- mem->online_type = -1;
+ mem->online_type = MMOP_OFFLINE;
return ret;
}
@@ -314,41 +247,27 @@
if (mem->state == MEM_OFFLINE)
return 0;
- /* Can't offline block with non-present sections */
- if (mem->section_count != sections_per_block)
- return -EINVAL;
-
return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
}
-static ssize_t
-store_mem_state(struct device *dev,
- struct device_attribute *attr, const char *buf, size_t count)
+static ssize_t state_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
{
+ const int online_type = memhp_online_type_from_str(buf);
struct memory_block *mem = to_memory_block(dev);
- int ret, online_type;
+ int ret;
+
+ if (online_type < 0)
+ return -EINVAL;
ret = lock_device_hotplug_sysfs();
if (ret)
return ret;
- if (sysfs_streq(buf, "online_kernel"))
- online_type = MMOP_ONLINE_KERNEL;
- else if (sysfs_streq(buf, "online_movable"))
- online_type = MMOP_ONLINE_MOVABLE;
- else if (sysfs_streq(buf, "online"))
- online_type = MMOP_ONLINE_KEEP;
- else if (sysfs_streq(buf, "offline"))
- online_type = MMOP_OFFLINE;
- else {
- ret = -EINVAL;
- goto err;
- }
-
switch (online_type) {
case MMOP_ONLINE_KERNEL:
case MMOP_ONLINE_MOVABLE:
- case MMOP_ONLINE_KEEP:
+ case MMOP_ONLINE:
/* mem->online_type is protected by device_hotplug_lock */
mem->online_type = online_type;
ret = device_online(&mem->dev);
@@ -360,7 +279,6 @@
ret = -EINVAL; /* should never happen */
}
-err:
unlock_device_hotplug();
if (ret < 0)
@@ -372,43 +290,44 @@
}
/*
- * phys_device is a bad name for this. What I really want
- * is a way to differentiate between memory ranges that
- * are part of physical devices that constitute
- * a complete removable unit or fru.
- * i.e. do these ranges belong to the same physical device,
- * s.t. if I offline all of these sections I can then
- * remove the physical device?
+ * Legacy interface that we cannot remove: s390x exposes the storage increment
+ * covered by a memory block, allowing for identifying which memory blocks
+ * comprise a storage increment. Since a memory block spans complete
+ * storage increments nowadays, this interface is basically unused. Other
+ * archs never exposed != 0.
*/
-static ssize_t show_phys_device(struct device *dev,
+static ssize_t phys_device_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
- return sprintf(buf, "%d\n", mem->phys_device);
+ unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
+
+ return sysfs_emit(buf, "%d\n",
+ arch_get_memory_phys_device(start_pfn));
}
#ifdef CONFIG_MEMORY_HOTREMOVE
-static void print_allowed_zone(char *buf, int nid, unsigned long start_pfn,
- unsigned long nr_pages, int online_type,
- struct zone *default_zone)
+static int print_allowed_zone(char *buf, int len, int nid,
+ unsigned long start_pfn, unsigned long nr_pages,
+ int online_type, struct zone *default_zone)
{
struct zone *zone;
zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
- if (zone != default_zone) {
- strcat(buf, " ");
- strcat(buf, zone->name);
- }
+ if (zone == default_zone)
+ return 0;
+
+ return sysfs_emit_at(buf, len, " %s", zone->name);
}
-static ssize_t show_valid_zones(struct device *dev,
+static ssize_t valid_zones_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct memory_block *mem = to_memory_block(dev);
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
- unsigned long valid_start_pfn, valid_end_pfn;
struct zone *default_zone;
+ int len = 0;
int nid;
/*
@@ -420,77 +339,71 @@
* The block contains more than one zone can not be offlined.
* This can happen e.g. for ZONE_DMA and ZONE_DMA32
*/
- if (!test_pages_in_a_zone(start_pfn, start_pfn + nr_pages,
- &valid_start_pfn, &valid_end_pfn))
- return sprintf(buf, "none\n");
- start_pfn = valid_start_pfn;
- strcat(buf, page_zone(pfn_to_page(start_pfn))->name);
+ default_zone = test_pages_in_a_zone(start_pfn,
+ start_pfn + nr_pages);
+ if (!default_zone)
+ return sysfs_emit(buf, "%s\n", "none");
+ len += sysfs_emit_at(buf, len, "%s", default_zone->name);
goto out;
}
nid = mem->nid;
- default_zone = zone_for_pfn_range(MMOP_ONLINE_KEEP, nid, start_pfn, nr_pages);
- strcat(buf, default_zone->name);
+ default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, start_pfn,
+ nr_pages);
- print_allowed_zone(buf, nid, start_pfn, nr_pages, MMOP_ONLINE_KERNEL,
- default_zone);
- print_allowed_zone(buf, nid, start_pfn, nr_pages, MMOP_ONLINE_MOVABLE,
- default_zone);
+ len += sysfs_emit_at(buf, len, "%s", default_zone->name);
+ len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
+ MMOP_ONLINE_KERNEL, default_zone);
+ len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
+ MMOP_ONLINE_MOVABLE, default_zone);
out:
- strcat(buf, "\n");
-
- return strlen(buf);
+ len += sysfs_emit_at(buf, len, "\n");
+ return len;
}
-static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
+static DEVICE_ATTR_RO(valid_zones);
#endif
-static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
-static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state);
-static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL);
-static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL);
+static DEVICE_ATTR_RO(phys_index);
+static DEVICE_ATTR_RW(state);
+static DEVICE_ATTR_RO(phys_device);
+static DEVICE_ATTR_RO(removable);
/*
- * Block size attribute stuff
+ * Show the memory block size (shared by all memory blocks).
*/
-static ssize_t
-print_block_size(struct device *dev, struct device_attribute *attr,
- char *buf)
+static ssize_t block_size_bytes_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
- return sprintf(buf, "%lx\n", get_memory_block_size());
+ return sysfs_emit(buf, "%lx\n", memory_block_size_bytes());
}
-static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL);
+static DEVICE_ATTR_RO(block_size_bytes);
/*
* Memory auto online policy.
*/
-static ssize_t
-show_auto_online_blocks(struct device *dev, struct device_attribute *attr,
- char *buf)
+static ssize_t auto_online_blocks_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
- if (memhp_auto_online)
- return sprintf(buf, "online\n");
- else
- return sprintf(buf, "offline\n");
+ return sysfs_emit(buf, "%s\n",
+ online_type_to_str[memhp_default_online_type]);
}
-static ssize_t
-store_auto_online_blocks(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t auto_online_blocks_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
{
- if (sysfs_streq(buf, "online"))
- memhp_auto_online = true;
- else if (sysfs_streq(buf, "offline"))
- memhp_auto_online = false;
- else
+ const int online_type = memhp_online_type_from_str(buf);
+
+ if (online_type < 0)
return -EINVAL;
+ memhp_default_online_type = online_type;
return count;
}
-static DEVICE_ATTR(auto_online_blocks, 0644, show_auto_online_blocks,
- store_auto_online_blocks);
+static DEVICE_ATTR_RW(auto_online_blocks);
/*
* Some architectures will have custom drivers to do this, and
@@ -499,9 +412,8 @@
* and will require this interface.
*/
#ifdef CONFIG_ARCH_MEMORY_PROBE
-static ssize_t
-memory_probe_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
{
u64 phys_addr;
int nid, ret;
@@ -520,7 +432,8 @@
nid = memory_add_physaddr_to_nid(phys_addr);
ret = __add_memory(nid, phys_addr,
- MIN_MEMORY_BLOCK_SIZE * sections_per_block);
+ MIN_MEMORY_BLOCK_SIZE * sections_per_block,
+ MHP_NONE);
if (ret)
goto out;
@@ -531,7 +444,7 @@
return ret;
}
-static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
+static DEVICE_ATTR_WO(probe);
#endif
#ifdef CONFIG_MEMORY_FAILURE
@@ -540,10 +453,9 @@
*/
/* Soft offline a page */
-static ssize_t
-store_soft_offline_page(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t soft_offline_page_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
{
int ret;
u64 pfn;
@@ -552,20 +464,14 @@
if (kstrtoull(buf, 0, &pfn) < 0)
return -EINVAL;
pfn >>= PAGE_SHIFT;
- if (!pfn_valid(pfn))
- return -ENXIO;
- /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */
- if (!pfn_to_online_page(pfn))
- return -EIO;
- ret = soft_offline_page(pfn_to_page(pfn), 0);
+ ret = soft_offline_page(pfn, 0);
return ret == 0 ? count : ret;
}
/* Forcibly offline a page, including killing processes. */
-static ssize_t
-store_hard_offline_page(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t hard_offline_page_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
{
int ret;
u64 pfn;
@@ -578,57 +484,39 @@
return ret ? ret : count;
}
-static DEVICE_ATTR(soft_offline_page, S_IWUSR, NULL, store_soft_offline_page);
-static DEVICE_ATTR(hard_offline_page, S_IWUSR, NULL, store_hard_offline_page);
+static DEVICE_ATTR_WO(soft_offline_page);
+static DEVICE_ATTR_WO(hard_offline_page);
#endif
-/*
- * Note that phys_device is optional. It is here to allow for
- * differentiation between which *physical* devices each
- * section belongs to...
- */
+/* See phys_device_show(). */
int __weak arch_get_memory_phys_device(unsigned long start_pfn)
{
return 0;
}
/*
- * A reference for the returned object is held and the reference for the
- * hinted object is released.
+ * A reference for the returned memory block device is acquired.
+ *
+ * Called under device_hotplug_lock.
*/
-static struct memory_block *find_memory_block_by_id(int block_id,
- struct memory_block *hint)
+static struct memory_block *find_memory_block_by_id(unsigned long block_id)
{
- struct device *hintdev = hint ? &hint->dev : NULL;
- struct device *dev;
+ struct memory_block *mem;
- dev = subsys_find_device_by_id(&memory_subsys, block_id, hintdev);
- if (hint)
- put_device(&hint->dev);
- if (!dev)
- return NULL;
- return to_memory_block(dev);
-}
-
-struct memory_block *find_memory_block_hinted(struct mem_section *section,
- struct memory_block *hint)
-{
- int block_id = base_memory_block_id(__section_nr(section));
-
- return find_memory_block_by_id(block_id, hint);
+ mem = xa_load(&memory_blocks, block_id);
+ if (mem)
+ get_device(&mem->dev);
+ return mem;
}
/*
- * For now, we have a linear search to go find the appropriate
- * memory_block corresponding to a particular phys_index. If
- * this gets to be a real problem, we can always use a radix
- * tree or something here.
- *
- * This could be made generic for all device subsystems.
+ * Called under device_hotplug_lock.
*/
struct memory_block *find_memory_block(struct mem_section *section)
{
- return find_memory_block_hinted(section, NULL);
+ unsigned long block_id = memory_block_id(__section_nr(section));
+
+ return find_memory_block_by_id(block_id);
}
static struct attribute *memory_memblk_attrs[] = {
@@ -666,20 +554,24 @@
memory->dev.offline = memory->state == MEM_OFFLINE;
ret = device_register(&memory->dev);
- if (ret)
+ if (ret) {
put_device(&memory->dev);
+ return ret;
+ }
+ ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory,
+ GFP_KERNEL));
+ if (ret)
+ device_unregister(&memory->dev);
return ret;
}
-static int init_memory_block(struct memory_block **memory, int block_id,
- unsigned long state)
+static int init_memory_block(unsigned long block_id, unsigned long state)
{
struct memory_block *mem;
- unsigned long start_pfn;
int ret = 0;
- mem = find_memory_block_by_id(block_id, NULL);
+ mem = find_memory_block_by_id(block_id);
if (mem) {
put_device(&mem->dev);
return -EEXIST;
@@ -689,43 +581,36 @@
return -ENOMEM;
mem->start_section_nr = block_id * sections_per_block;
- mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
mem->state = state;
- start_pfn = section_nr_to_pfn(mem->start_section_nr);
- mem->phys_device = arch_get_memory_phys_device(start_pfn);
mem->nid = NUMA_NO_NODE;
ret = register_memory(mem);
- *memory = mem;
return ret;
}
-static int add_memory_block(int base_section_nr)
+static int add_memory_block(unsigned long base_section_nr)
{
- struct memory_block *mem;
- int i, ret, section_count = 0;
+ int section_count = 0;
+ unsigned long nr;
- for (i = base_section_nr;
- i < base_section_nr + sections_per_block;
- i++)
- if (present_section_nr(i))
+ for (nr = base_section_nr; nr < base_section_nr + sections_per_block;
+ nr++)
+ if (present_section_nr(nr))
section_count++;
if (section_count == 0)
return 0;
- ret = init_memory_block(&mem, base_memory_block_id(base_section_nr),
- MEM_ONLINE);
- if (ret)
- return ret;
- mem->section_count = section_count;
- return 0;
+ return init_memory_block(memory_block_id(base_section_nr),
+ MEM_ONLINE);
}
static void unregister_memory(struct memory_block *memory)
{
if (WARN_ON_ONCE(memory->dev.bus != &memory_subsys))
return;
+
+ WARN_ON(xa_erase(&memory_blocks, memory->dev.id) == NULL);
/* drop the ref. we got via find_memory_block() */
put_device(&memory->dev);
@@ -736,11 +621,13 @@
* Create memory block devices for the given memory area. Start and size
* have to be aligned to memory block granularity. Memory block devices
* will be initialized as offline.
+ *
+ * Called under device_hotplug_lock.
*/
int create_memory_block_devices(unsigned long start, unsigned long size)
{
- const int start_block_id = pfn_to_block_id(PFN_DOWN(start));
- int end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
+ const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
+ unsigned long end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
struct memory_block *mem;
unsigned long block_id;
int ret = 0;
@@ -749,23 +636,21 @@
!IS_ALIGNED(size, memory_block_size_bytes())))
return -EINVAL;
- mutex_lock(&mem_sysfs_mutex);
for (block_id = start_block_id; block_id != end_block_id; block_id++) {
- ret = init_memory_block(&mem, block_id, MEM_OFFLINE);
+ ret = init_memory_block(block_id, MEM_OFFLINE);
if (ret)
break;
- mem->section_count = sections_per_block;
}
if (ret) {
end_block_id = block_id;
for (block_id = start_block_id; block_id != end_block_id;
block_id++) {
- mem = find_memory_block_by_id(block_id, NULL);
- mem->section_count = 0;
+ mem = find_memory_block_by_id(block_id);
+ if (WARN_ON_ONCE(!mem))
+ continue;
unregister_memory(mem);
}
}
- mutex_unlock(&mem_sysfs_mutex);
return ret;
}
@@ -773,28 +658,27 @@
* Remove memory block devices for the given memory area. Start and size
* have to be aligned to memory block granularity. Memory block devices
* have to be offline.
+ *
+ * Called under device_hotplug_lock.
*/
void remove_memory_block_devices(unsigned long start, unsigned long size)
{
- const int start_block_id = pfn_to_block_id(PFN_DOWN(start));
- const int end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
+ const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
+ const unsigned long end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
struct memory_block *mem;
- int block_id;
+ unsigned long block_id;
if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) ||
!IS_ALIGNED(size, memory_block_size_bytes())))
return;
- mutex_lock(&mem_sysfs_mutex);
for (block_id = start_block_id; block_id != end_block_id; block_id++) {
- mem = find_memory_block_by_id(block_id, NULL);
+ mem = find_memory_block_by_id(block_id);
if (WARN_ON_ONCE(!mem))
continue;
- mem->section_count = 0;
unregister_memory_block_under_nodes(mem);
unregister_memory(mem);
}
- mutex_unlock(&mem_sysfs_mutex);
}
/* return true if the memory block is offlined, otherwise, return false */
@@ -828,38 +712,77 @@
};
/*
- * Initialize the sysfs support for memory devices...
+ * Initialize the sysfs support for memory devices. At the time this function
+ * is called, we cannot have concurrent creation/deletion of memory block
+ * devices, the device_hotplug_lock is not needed.
*/
-int __init memory_dev_init(void)
+void __init memory_dev_init(void)
{
- unsigned int i;
int ret;
- int err;
- unsigned long block_sz;
+ unsigned long block_sz, nr;
+
+ /* Validate the configured memory block size */
+ block_sz = memory_block_size_bytes();
+ if (!is_power_of_2(block_sz) || block_sz < MIN_MEMORY_BLOCK_SIZE)
+ panic("Memory block size not suitable: 0x%lx\n", block_sz);
+ sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
ret = subsys_system_register(&memory_subsys, memory_root_attr_groups);
if (ret)
- goto out;
-
- block_sz = get_memory_block_size();
- sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
+ panic("%s() failed to register subsystem: %d\n", __func__, ret);
/*
* Create entries for memory sections that were found
* during boot and have been initialized
*/
- mutex_lock(&mem_sysfs_mutex);
- for (i = 0; i <= __highest_present_section_nr;
- i += sections_per_block) {
- err = add_memory_block(i);
- if (!ret)
- ret = err;
+ for (nr = 0; nr <= __highest_present_section_nr;
+ nr += sections_per_block) {
+ ret = add_memory_block(nr);
+ if (ret)
+ panic("%s() failed to add memory block: %d\n", __func__,
+ ret);
}
- mutex_unlock(&mem_sysfs_mutex);
+}
-out:
- if (ret)
- printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
+/**
+ * walk_memory_blocks - walk through all present memory blocks overlapped
+ * by the range [start, start + size)
+ *
+ * @start: start address of the memory range
+ * @size: size of the memory range
+ * @arg: argument passed to func
+ * @func: callback for each memory section walked
+ *
+ * This function walks through all present memory blocks overlapped by the
+ * range [start, start + size), calling func on each memory block.
+ *
+ * In case func() returns an error, walking is aborted and the error is
+ * returned.
+ *
+ * Called under device_hotplug_lock.
+ */
+int walk_memory_blocks(unsigned long start, unsigned long size,
+ void *arg, walk_memory_blocks_func_t func)
+{
+ const unsigned long start_block_id = phys_to_block_id(start);
+ const unsigned long end_block_id = phys_to_block_id(start + size - 1);
+ struct memory_block *mem;
+ unsigned long block_id;
+ int ret = 0;
+
+ if (!size)
+ return 0;
+
+ for (block_id = start_block_id; block_id <= end_block_id; block_id++) {
+ mem = find_memory_block_by_id(block_id);
+ if (!mem)
+ continue;
+
+ ret = func(mem, arg);
+ put_device(&mem->dev);
+ if (ret)
+ break;
+ }
return ret;
}
--
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